Iranian President Mahmoud Ahmadinejad, center, is surrounded by bodyguards as he arrives to address a public gathering, in Hamedan about 204 miles southwest of the capital Tehran, Iran, Wednesday. A hand-made grenade exploded close to Mahmoud Ahmadinejad's convoy in western Iran but the Iranian president was not hurt.

The president’s office and official Iranian media sites quickly denied reports of the attack, which came just days after Mr. Ahmadinejad warned that "stupid Zionists" had hired mercenaries to assassinate him.

The conservative Iranian website Khabar first reported an assassination attempt, in the Iranian city of Hamadan, where Ahmadinejad later addressed huge crowds. BBC correspondent Jon Leyne says it’s the first assassination attempt against Ahmadinejad that he is aware of since the president rose to power in 2005.

(Leyne was the BBC’s chief TV reporter in Iran until he was expelled amid election protests last year. The government accused him of "false news and reports, ignoring impartiality, supporting the insurgents, trampling the rights of the Iranian nation, fanning the unrest and also provoking public opinion.")

"If confirmed as an assassination attempt, it would be the first one I have heard of during his presidency, although the president claimed the Americans had a plot to kidnap him when he traveled to Iraq a couple of years ago," he said on the BBC.

Speaking to Press TV, an informed source in Iran's presidential office has rejected as false the reports of grenade attack on Iranian President Mahmoud Ahmadinejad.

… The source denied the reports, saying no such attack took place.

Khabar removed the article from its website.

The semi-official Fars news agency, which had also initially reported that Ahmadinejad had been targeted by a grenade, later changed its report as well – saying the source of the explosion was actually a firecracker, reported the BBC. The firecracker was meant to welcome Ahmadinejad, according to the Iranian TV station Al-Alam.

The British newspaper the Guardian has posted a photo it claims depicts Ahmadinejad’s bodyguards searching for the source of an explosion.

"I also gathered information from some journalists who were part of Ahmadinejad's convoy and they said they haven't heard or seen anything.I think it must have been something so insignificant or so small that nobody noticed anything."

Ahmadinejad, by contrast, has heavily criticized America’s strong sway on the international scene. He routinely casts himself as a man of the people, often passing through throngs on the provincial visits that have become a staple of his presidency, which is now in its second term.